Assessment of regional and total skeletal metabolism using ¹⁸F-NaF PET/CT in patients with chronic kidney disease

The study aims to assess regional and total bone metabolic activity in patients with chronic kidney disease using Na[¹⁸F]F PET and correlation between semi-quantitative indices and blood parameters.

Seventy-two subjects (mean age 61.8 ± 13.8 years) were included. Of these 24/72 patients had end-stage renal disease (ESRD) (GFR < 15 mL/min/1.73 m²), 38/72 had chronic kidney disease (CKD) (GFR between 60 and 15 mL/min/1.73 m²), and 10/72 were controls with normal renal function. All subjects underwent Na[¹⁸F]F PET-CT with a dose activity of 0.06 mCi/Kg. Regional and total skeletal metabolism were assessed with mean SUVs in a skeletal volume of interest (VOI), bone to soft tissue index (B/S), global SUV mean (GSUV mean) of the whole bone, and uptake in the femoral neck.

Statistically significant differences were observed in a number of ¹⁸F-NaF metrics like femoral neck metabolism in CKD and ERSD groups in comparison to control in right (P = 0.003) and left femur (P = 0.006), bone to soft tissue index in the femur (P = 0.016) and GSUV₅ (P = 0.006). There is also a significant difference in SUV mean in lumbar vertebrae (L1–L4) among CKD, ESRD, and controls. There was a moderate correlation between ¹⁸F-NaF PET scan uptake and blood parameters such as ALP and PTH. Na[¹⁸F]F uptake parameters were significantly different in low versus high bone turnover state.

The assessment of total skeleton and regional metabolism and bone turnover in CKD patients is feasible with Na[¹⁸F]F PET. Na[¹⁸F]F can help to detect early changes in bone metabolism and assess the progression of bone disease in this complex condition. Quantification with Na[¹⁸F]F PET might provide better assessment of the bone turnover. The difference in Na[¹⁸F]F uptake in CKD compared to controls is likely related to a change in bone turnover which, however, requires further validation.